<!DOCTYPE html>
<script src="../../resources/run-after-layout-and-paint.js"></script>
<svg width="400px" height="400px">
  <text font-size="40">
    <tspan dy="40">1</tspan>
    <tspan dy="40">4</tspan>
  </text>
</svg>
<script>
runAfterLayoutAndPaint(function() {
  var tspans = document.querySelectorAll('tspan');
  tspans[0].textContent = '123';
  tspans[1].textContent = '456';
}, true);
</script>
